Refrigeration system for ice rinks



Sept. 16, 1969 R. B. HOLMSTEN 3,466,892

REFRIGERATION SYSTEM FOR ICE RINKS Filed Oct. 9, 1957 I N vEN TOR. Baum 3. HOLMSIEA/ g 4 7 TOE/V51 8 United States Patent US. Cl. 62-467 7 Claims ABSTRACT OF THE DISCLOSURE A system for providing a refrigerant to a zone or area retaining a medium to be chilled, the system including a compressor means for compressing a refrigerant, means for delivering the compressed refrigerant to a low pressure receiver vessel, and means for passing refrigerant condensate from said low pressure vessel to a pumper drum vessel. The system further includes means for utilizing liquid refrigerant, under pressure, for propelling fluid retained in the pumper drum from this drum to the zone or area retaining the medium from which heat is being abstracted.

The present invention relates generally to an improved system or technique for providing a medium of exchange or for the abstracting of thermal energy in relatively large installations such as, for example, skating rinks or the like. The system provides a means for conducting or delivering or circulating liquid refrigerant to the area being refrigerated, wherein a portion of the liquid refrigerant undergoes a phase transformation to deliver a refrigerating effect to the installation, the refrigerant being circulated to the refrigeration area by means of the propulsion achieved by fluids in the liquid state under high pressure and substantially direct y from the compressor device. This technique eliminates the necessity of transmission or circulation of liquid refrigerant at extremely low temperatures, and permits operation at a reasonably constant temperature which is in the range of between about l18 degrees F. This temperature is one which results in an ice surface which is deemed ideal for ice hockey or figure skating, and this system accomplishes the result with unusually high efficiency.

At the present time, refrigerants are normally utilized which employ an indirect system of cooling. According y, the refrigerant is normally circulated through a medium which is chilled to an appropriate low temperature, after which the chilled medium is circulated through the area where heat is being abstracted. The horsepower requirements of these systems are substantial, and their efliciency is traditionally very low. In accordance with the present invention, refrigerant fluid is transmitted directly through the refrigeration area at a reasonable temperature.

Briefly, in accordance with the present invention, the refrigerant material is passed through a compressor wherein it is transformed in phase so that it is substantialy entirely in the liquid state. This material is ultimately passed through a pressure reducing or demand valve and on to a low pressure receiver wherein a portion of the liquid undergoes a phase transformation to the gaseous state to control the temperature of the material therein at a modestly low temperature level. The liquid remaining in this receiver is permitted to flow or drain to a pumper drum, and when the pumper drum becomes substantially entirely fi led, the pumper drum is coupled by means of suitable valving, substantially directly to the output of the compressor, which output is at a relatively higher pressure, and this fluid under the influence of this higher pressure is utilized to force the chilled refrigerant from the pumper drum out into the rink area. To accomplish this, the fluid is forced under pressure into a header and distribution sys- 3,466,892 Patented Sept. 16, 1969 ice tem, and is accordingly distributed out into the refrigeration area. After passing through the refrigeration area, the fluid, in both liquid and gaseous phases, is returned to the low pressure receiver. The evaporant present in the low pressure receiver is transmitted on a continuous basis to the compressor-s for continuing the cycle.

Therefore, it is an object of the present invention to provide an improved system for the transmission or circulation or refrigerant through a refrigeration zone, the transmission utilizing the circulation of chilled refrigerant fluid in the liquid state directly into the header zone of an area being refrigerated.

It is yet a further object of the present invention to provide an improved system for the circulation or transmission of fluid refrigerant in liquid phase, the refrigerant being propelled through the system from a liquid refrigerant pumping drum coupled intermittently to the output of the refrigerator compressor.

It is yet a further object of the present invention to provide a system for circulating fluid refrigerant in the liquid state through an area exposed to a refrigeration effect, the zone accommodating the phase transformation of at least a portion of the refrigeration fluid from liquid to gaseous state, the refrigerant being at a substantially constant temperature level across the entire area undergoing refrigeration.

It is still a further object of the present invention to provide an improved refrigeration system which utilizes the transmission of refrigerant in liquid phase directly into the area being refrigerated, the refrigerant being supplied on an intermittent basis from a pumper drum which is intermittently coupled to the output of a refrigerator compressor.

Other and further objects of the present invention will become apparent to those skilled in the art upon a study of the following specification, appended claims, and accompany'ing drawings wherein:

FIGURE 1 is a schematic diagram of one typical installation employing the improved system aspects of the present invention; and

FIGURE 2 is a vertical sectional view of a major liquid distribution head which is preferably utilized in the system of the present invention.

In accordance with the preferred modification of the present invention, the refrigeration system generally designated 10 includes a pair of compressors 11 and 12, these compressors being coupled in parallel relationship for treating the refrigerant which is being delivered into the area or zone being refrigerated, such as the skating rink shown at 13. The system includes certain other major components including a condenser 15, a liquid storage vessel 16, a low pressure receiver chamber or vessel 17, and a pair of pumper drums 18 and 19. The individual components are coupled together by means of suitable conduits, as indicated, and as more fully explained hereinafter.

Referring to the system, the compressors 11 and 12 deliver a pre-selected refrigerant, such as, for example, Freon-22 to a main conduit 20, the output of the compressors 11 and 12 being coupled in parallel fluid relationship. These compressors are driven by any suitable source of power, such as, for example, an electrical power source or an internal combustion engine. Conduit 20 extends to and communicates with the condenser 15 which is operated in a conventional fashion. The output of the condenser 15 is transmitted by means of the conduit segment 22 and the conduit 23 through a controlled metering valve 24 and thence into the liquid storage vessel 16. Liquid storage vessel 16 is provided with a pair of outlet conduits, these being shown at 26 and 27. Conduit 26 is provided with a pair of control valves, for example gate valves 28 and 29, along with a pressure reducing or demand flow control valve 30. A bypass is provided, as indicated, at 31 to accommodate the system when the valve 30 is not being utilized, valves 28 and 29 being utilized to isolate valve 30 from the system. Outlet 27 extends from the liquid storage vessel 16 to a juncture point with the liquid storage vessel bypass line 33, the flow in line 33 being controlled by valve 34. Line 27 extends to a second juncture point or fluid divider point as at 55 where the fluid is driven or carried for transmission directly into one of the pumper drums, such as pumper drum 18, for a purpose as will be more fully explained hereinafter or for transmission to the vessel 17.

Following its transmission into the low pressure receiver 17, a portion of the liquid transmitted is transformed into the vapor phase, and the remaining material remains in the liquid phase. The liquid is removed from the low pressure receiver 17 by gravity through conduit 36, which is provided with a servicing valve 37, and ultimately into the pumper drum 18. Of course, a suitable conduit 39 may be coupled to conduit 36 in order to carry refrigerant fluid in liquid state on an alternating cycle basis to the second pumper drum 19. Suitable check valves such as are shown at 40 and 41 are utilized to isolate the pumper drums 18 and 19 from the supply conduits 36 and 39 and from the low pressure receiver 17 when the drums are subjected to high pressure. The pumper drums 18 and 19 are each provided with discharge conduits 43 and 44 which, by virtue of the check valves 45 and 46, are effectively isolated, one from the other, while both are coupled to the delivery conduit 48 supplying chilled refrigerant to the rink zone.

Conduit 48 is coupled to the trunk distribution head 50 as shown, and header 50 is provided with a plurality of distribution lines such as, for example, the distribution lines 5151. A refrigerant collecting header is utilized to collect the refrigerant from lines 5151 and deliver it into line 52 for ultimate return to the low pressure receiver 17. Service valve 53 may be employed along line 52 as required.

In order to provide the force necessary to transmit the refrigerant from the pumper drums through line 48 and retain this refrigerant in liquid phase, attention is directed to the output 27 of the liquid storage vessel 16. Line 27 couples liquid storage vessel 16 to a juncture point 55, solenoid valve 56 and check valve 57 being interposed along line 27 between the liquid storage vessel 16 and the juncture point 55. Line 58 connects the juncture point 55 to the inlet of the pumper drum 18. A parallel system for providing high pressure to the pumper drum 19, this including conduit 59 which extends between the line 27 and a juncture point 60. A solenoid valve 61 and a check valve 62 are interposed along line 50 for control. Conduit 68 has a segment coupling juncture point 60 to the inlet of pumper drum 19.

Juncture point 55 is coupled also to a conduit or line 64 which conduit is, in turn, coupled to the low pressure receiver 17, through check valve 65 and solenoid valve 66 for the purpose of venting drum 18. Similarly, an upper segment of line 68 extends from juncture point 60 to the low pressure receiver 17, this upper segment of line 68 including check valve 69 and solenoid valve 70.

As previously indicated, pumper drums 18 and 19 are filled by gravity through lines 36 in the case of pumper drum 18 and a combination of lines 36 and 39 in the case of pumper drum 19. In order to accommodate this gravity fill, and With specific reference to pumper drum 18, conduit 58 functions as a vent during the filling operation, and with solenoid valve 56 in a closed position and solenoid valve 66 in an open position, refrigerant in gaseous phase moves from pumper drum 18 along line 58 to juncture point 55, and thereafter from juncture 55 to the low pressure receiver 17 by Way of line 64. In a similar fashion, pumper drum 19 is vented to low pressure receiver 17. When the pumper drum is filled to an upper level as sensed by a float or fluid level sensor 72, the disposition of solenoid valves 56 and 66 is reversed, and the high pressure fluid from the liquid storage vessel 16 is transmitted directly into the pumper drum 18 by way of line 27 from liquid storage vessel 16 to juncture point 55, and then through line 58 to pumper drum 18. This operation is continued until the level in pumper drum 18 is reduced to the lower level or point indicated by liquid level sensor 73. During the discharge of refrigerant from storage vessel 16 to pumper drum 18, a portion of the fluid in vessel 16 may be transformed to the gaseous phase. When the lower level point is reached in drum 18, the disposition of the solenoid valves 56 and 66 is again reversed, and pumper drum 18 resumes its filling cycle. In a similar fashion, pumper drum 19 is filled and emptied, and preferably the two pumper drums operate alternately in order to provide a substantially continuous flow of chilled refrigerant in liquid phase to the header 50 by way of delivery conduit or line 48.

Since most fluorinated hydrocarbons such as constitute Freon-22 are completely miscible or compatible with the oils utilized to lubricate the compressors, it is frequently desirable to provide a bleed line to continuously separate the oil from the refrigerant. Thus, the bleed line 75 is provided between the low pressure receiver 17 and a refrigerant-oil separator 76. The separator is provided with a discharge line 77 to carry the separated oil back to an oil receiver 78, and ultimately into the compressors 11 and 12, respectively, as shown. Line 79 and its check valve 80 are utilized to permit transfer of the liquid refrigerant from the separator 76 to the line 48.

Pressure gauge and thermometer indicators are frequently desirable, these being shown for example, along delivery conduit 48 as at 81. It will be appreciated that instrumentation is not essential to the operation of a calibrated system, however for purposes of uniform operation, such instrumentation is normally desired.

Attention is now directed to FIGURE 2 of the drawings wherein the trunk distribution head is illustrated in detail. This head 50 is utilized to confine the refrigerant delivered from the pumping drum, the head 50' being provided with a plurality of liquid sub-feeder lines such as the line 91. Each liquid sub-feeder line is in turn provided with a plurality of distribution openings. conventionally, 18 such distribution openings are provided for each liquid sub-feeder line but other numbers may be used. These distribution heads in turn lead to the individual lines 5151 which extend across the refrigeration area. It is important that either the line length of the individual lines extending from the distributor head be substantially equal or that other controls be utilized in order to equalize flow and avoid the provision of warm or cold isolated areas within the refrigeration area. It will be appreciated, of course, that other distribution systems may be utilized with the system of the present invention.

The system described herein finds particular utility in skating rink applications since the chilled refrigerant which is driven through the distribution system is maintained substantially in the liquid state during its transfer therethrough. There is, of course, a certain transformation from liquid to gaseous phase, however, since the refrigerant is exposed to a modest increase in pressure during its movement through the distribution lines, the degree of transformation from liquid to gaseous phase is minimal. Thus, refrigerant entering the distribution head at 15-18 degrees F. will normally leave this distribution head at a temperature of no less than about 12 degrees F.

The efliciency of this system is also significantly high. Since the degree of efiiciency of a compressor device is related at least in part to the temperature differential existing across the compressor, that is, from inlet to outlet, the present system is one capable of high efliciency since the temperature differential is maintained at a substantially minimal value.

It will be further understood that various changes may be made in the form, details, arrangements andproportions of the parts without departing from the scope of the invention as set forth in the appended claims.

What is claimed is:

1. In a refrigeration system for delivering chilled refrigerant substantially entirely in the liquid state to a zone where heat is being abstracted:

(a) compressor means having an inlet conduit for receiving refrigerant at one pressure, and outlet conduits for delivering an output of refrigerant to said outlet conduit under a relatively higher pressure,

(b) means for delivering said output to a first storage vessel wherein said output is received, at least partially evaporated to achieve a refrigeration effect therein, and maintained therein at a relatively lower pressure;

(0) means for intermittently delivering refrigerant in liquid phase from said first storage vessel to a second storage vessel wherein said delivered refrigerant is received and normally maintained at said relatively lower pressure;

(d) means for intermittently coupling said second storage vessel substantially directly to said compressor outlet to subject the refrigerant therein to said relatively higher pressure and While coupled thereto, deliver said output thereto;

(e) means for delivering the refrigerant from said second storage vessel under the influence of said compressor output to the zone where heat is being extracted; and

(f) means for delivering the refrigerant from said zone where heat is being extracted to said first storage vessel.

2. The refrigeration system as defined in claim 1 being particularly characterized in that a plurality of said second storage vessels are provided for alternate coupling to said first storage vessel and to said compressor outlet.

3. The refrigeration system as defined in claim 2 being particularly characterized in that said plurality of second storage vessels function independently and in alternating sequence.

4. The refrigeration system as defined in claim 1 being particularly characterized in that the zone where heat is being abstracted is a skating rink.

5. The refrigeration system as defined in claim 1 being particularly characterized in that an oil separation apparatus is interposed between said first storage vessel and said compressor means.

6. The refrigeration system as defined in claim 1 being particularly characterized in that a buffer storage vessel is disposed between said compressor outlet and the inlet to said second storage vessel.

7. The refrigeration system as defined in claim 1 being particularly characterized in that the refrigerant flows from said first storage vessel to said second storage vessel by means of gravity.

References Cited UNITED STATES PATENTS 2,878,651 3/1959 Heinzelman 62235 3,307,372 3/ 1967 Kenison 62235 3,352,124 11/ 1967 Watkins 62509 LLOYD L. KING, Primary Examiner US. 01. X.R. 62235, 509 

